Diagonal mandrel transverse winder

ABSTRACT

Method and apparatus for winding rolls of sheet material parent as toilet tissue, towels, and the like. A number of parent rolls is selected such that the total width of the rolls is about equal to the desired sheet length in the rewound roll. The parent rolls are unwound simultaneously in abutting relationship so that the sheets are generally edge-to-edge or slightly overlapping. At the same time mandrels pass over the sheets building up rolls in an effective diagonal path. Variations include forming sheets having two or more plies.

' United States Patent [1 1 Caple et al.

[ Mar. 26, 1974 DIAGONAL MANDREL TRANSVERSE WINDER Inventors: Ira Caple; Charles T. Banks, both of Neenah, Wis.; Jorg F. Voss, Koblenz-Rhinehafen, Germany Kimberly-Clark Corporation, Neenah, Wis.

May 17, 1971 Assignee:

Filed:

Appl. No.:

US. Cl. 242/56 R, 83/408, 83/519, 93/20 Int. Cl B65h 17/24, B65h 79/00 Field of Search 242/56 R, 56.2, 56.3, 56.4, 242/565, 56.6, 56.7, 56.8, 59, 56.1; 93/20, 77, 80, 81; 83/408, 519

References Cited UNITED STATES PATENTS 11/1969 Banks 242/56 R 2,461,246 2/1949 Weyenberg 242/56 R 2,599,942 6/1952 Roen 242/56 R 2,698,662 l/l955 Moody 242/56 R X Primary Examiner.lohn W. Huckert Assistant Examiner-John M. Jillions Attorney, Agent, or Firm-Daniel J. Hanlon, Jr.; William D. Herrick; Raymond J. Miller [57] ABSTRACT Method and apparatus for winding rolls of sheet material parent as toilet tissue, towels, and the like. A number of parent rolls is selected such that the total width of the rolls is about equal to the desired sheet length in the rewound roll. The parent rolls are unwound simultaneously in abutting relationship so that the sheets are generally edge-to-edge or slightly overlapping. At the same time mandrels pass over the sheets building up rolls in an effective dliagonal path. Variations include forming sheets having two or more plies.

13 Claims, 7 Drawing Figures 20g 22f 24b 20 240 DIAGONAL MANDREL TRANSVERSE WINDER DESCRIPTION OF THE INVENTION Our invention relates generally to devices and processes for winding rolls of sheet material.

More particularly, our invention relates to winders and methods for winding at very high rates without requiring excessive rotational speeds.

Still more particularly, our invention relates to the winding of rolls by transverse movement of mandrels across a plurality of travelling sheets.

Many processes call for one or more steps requiring sheet material tobe formed into rolls. For example, in the paper industry such products as paper towels and bathroom tissue are conventionally wound on paper cores as consumer products. These commercial rolls are commonly formed from larger parent rolls by splitting the rolls into shorter lengths and rewinding them onto the paper cores. In order for this operation to be highly efficient the winders must operate at extremely rapid speeds in the range of 2,000 to 3,000 fpm and even higher. The primary problems associated with these high speeds is low overall efficiency, but others include increased waste, expensive sophisticated equipment, and a greater dependency on uniform material properties and highly skilled operators. Furthermore, the state of the art is such that further substantial increases in winder speed at this time are highly unlikely; therefore, increases in winding capacity must be sought by other means.

One example of ways previously used to increase winding capacity is to utilize longer parent rolls thus allowing a greater number of cores to be simultaneously wound. However, with present equipment the length of such rolls is limited, and this method, too, is approaching its present maximum capacity. In addition, delays caused by equipment failures in the wrapping and packaging operations have had a cumulative effect in increasing the downtime of expensive, high-speed winders. It has, therefore, become necessary to search for new concepts unrestricted by the limitations inherent in present equipment.

It is a primary object of our invention to provide a method capable of greatly increased winding capacity.

It is further an object of our invention to provide apparatus for carrying out this method.

Related to the above objectives, our invention provides a winder that is relatively simple in operation and more durable due to reduced rotational speed requirements.

Other objects and advantages of our invention will become apparent to those skilled in this art upon reference to the detailed description and to the drawings, in which,

FIG. 1 is a schematic perspective illustration of a winding operation in accordance with our invention,

FIG. 2 is a side elevational view of the slitter mechanism for one of the webs.

FIGS. 3 and 4 illustrate successive stages in the operation of our invention.

FIGS. 5 to 7 are vector diagrams showing the effect of winder-parent roll speed relationships.

The art of winding rolls of materials is crowded and highly developed. Sophisticated winders have been developed capable of very high speeds and production rates. However, the development of this art has been devoted primarily to increasing the rotational speed of more or less conventional arrangements with some emphasis on larger parent rolls. Very few truly new winding concepts have been devised, and the prevalence of conventional devices is a testimony to the lack of success achieved by those few.

Such conventional devices commonly produce rolls of toilet tissue or toweling, for example, by winding onto a core a wide width of web which is perforated on lines running to the length of the web, with the web travelling directly to the core at 90 with respect to the longitudinal center of the core. This results, of course, in a finished product roll having the perforations and direction of intended tear at 90 to the most easily torn (machine) direction. After a desired diameter of toweling or tissue has been so wound onto a core, winding is discontinued, and the long, cylindrical length of wound paper is cut into segments so as to produce individual, relatively short, consumer length rolls. The toweling and tissue is preferably so wound in multiple plies, and the transverse perforation lines of the multiple plies are in register so that multiple-ply sheets of the toweling or tissue may be detached individually from a completed, relatively short length roll.

This conventional winding arrangement has been developed to such a state that the benefits to be derived from higher speed operation are usually substantially offset by the increased complexity of equipment involved and its more rapid deterioration. In addition, the use of high speed winders is accompanied by the production of greater amounts of waste or substandard product due to the fact that a relatively brief period of malfunction or downtime is sufficient to damage a great amount of material travelling at speeds of 2,000 feet per minute or more.

Our invention, on the other hand, avoids these difficulties by providing a totally different approach which results in greatly increased winding capacity while providing for operation at reduced rotational speeds.

Turning now to the drawings wherein like characters of reference designate like parts in the several views,

FIG. 1 schematically illustrates the operation of a winder produced in accordance with our invention. Parent rolls 20a, 20b, 20c, etc. are placed in offset rela tionship to one another so that the joints at the sheet edges 22a, 22b, 220, etc. on the first and second plies are offset. In this manner, a single, composite two-ply sheet is formed having an overall width equal to the lineal feet in the product roll being manufactured. Rolls 24a, 24b, 24c represent typical feed rolls, calender, printer, etc. which may be desired depending on the appearance and construction of the end product. Sheet length slitters or embossers 26 provide the perforations or scoring 27 for tearing individual sheets or towels.

The sheets 28a, 28b, 280, etc. are carried and supported by endless moving belts 30,, 32, 34, and 36. As the sheets move on the belts, cro:ssdeckle slitters 37 and 38 travel angularly to the path of sheet travel. Preferably driven by the same mechanism (not shown) are mandrels 40, 42, and 44 which rotate and collect the sheet into logs as they traverse the combined widths of the parent rolls. Due to the relative movement of the mandrels and the sheets, the logs may be formed continuously along the same angular path. It will be recog nized that the particular angle is not critical and may be selected for optimum results with any combination of web and mandrel traverse speeds (FIGS. 5-7). For example, when the mandrels traverse the cross-deckle at the same speed that the sheet travels, the angle, alpha, will be 45 (FIG. 6), and the log will be rolled up square with respect to the unwinding sheets. However, this arrangement is by no means necessary, and other relative speeds or angles may be preferred for operating convenience or other reasons as will be discussed further with respect to FIGS. 5-7. Each of the parent rolls a, 20b, 206, etc. is, of course, supported as by means of a standard 46 (shown schematically with roll 20d in FIG. 1) having spaced upwardly extending pedestals 48 and 50 receiving between them an axle 52 extending through the center of the paper roll. The other rolls and slitters are suitably supported by conventional supports which have been omitted for clarity.

FIG. 2 shows a schematic side view of gang slitters 26 which may be used if perforated sheets are desired. Each slitter comprises a hard surfaced rotary drum 54 and a series of spaced slitter wheels 56 located directly above the drum 54, each having a pressure nip therewith and held by supports 55. The slitter wheel 56 has a plurality of spaced notches 56a in its periphery, and otherwise each slitter wheel may be sharpened to a knife edge on its periphery. Our invention, however, avoids the necessity for such slitters since the finished product, when torn, will tend to tear across the sheet anyway. Therefore, the gang slitters may be omitted entirely or replaced, if desired, by an embossing arrangement wherein slitter wheels 56 are replaced by embossing disks which score the sheet without actually cutting It.

The operation of our invention may be more clearly understood by reference to FIGS. 3 and 4. These figures represent successive operational phases beginning at time zero in FIG. 3. In FIG. 3 mandrel 40 and heavy paper core 62 are in position to rotate and pick up sheets 28a at points A and B. As the mandrel and the sheets move, a diagonal path is traversed across the sheets to the position C-D shown in FIG. 4. There mandrel 40 has built up a partial roll 58 and is picking up sheet 28b at points C and D which have moved to that position as parent roll 20b unwinds simultaneously with the mandrel traverse. At points E-F another roll 60 is nearing completion of its traverse when it will be removed and slit, if desired, into consumer length rolls. The arrangement of FIG. 1 operates similarly except that two plies are wound instead of one.

In the arrangement of overlapping parent rolls 20a, 20b, 20c, etc. (FIG. 1) utilized in the production of multipleply tissue, it is preferred that the first and last rolls be one-half the length of the others so that the edges of the sheets will match.

Referring now to FIGS. 5 to 7, the selection of a diagonal cross-deckle slitter path will be described. The particular cross-deckle angle, alpha, is not critical; however, it is generally desirable to have the sheet wound up square or in a manner providing that the machine direction is parallel to the core axis. The choice of angle, therefore, depends upon the relative rates of sheet unwind from the parent rolls and the traverse of the cross-deckle slitters. For example, as illustrated in FIG. 5, suppose the parent rolls are unwinding onto the belts at some rate, S, and it is desired that the effective cross deckle traverse be at twice that rate or 25. In that case, the angle of traverse, alpha, would be about 63'/2 as shown. Of course, the actual rate of traverse R in the angular direction will be something more than 25, e.g. about 2.2 S in this case. FIGS. 6 and 7 show corresponding diagrams for examples where the effective traverse rate is equal to and one-half the unwind rate, respectively.

The apparatus and method for making individual rolls of transversely perforated paper as above described is particularly suitable for making toweling or toilet tissue, both of which are basically tissue paper which has been creped off the heated drier drum of the papermaking machine so that it has substnatial stretch. However, our invention is ideally suited for any winding operation where it is desired to form rolls at a rapid rate. Any number of web plies may be combined to form an integral sheet.

The parent or supply rolls 20a, 20b, 20c, etc. may, of course, vary considerably in axial length, and, in general, it is advantageous to make the parent rolls as wide as possible. Whereas earlier devices have often required the splitting of rolls as produced on the paper machines, our invention will easily accommodate the entire width of these rolls, commonly 20-24 feet, and even wider rolls if desired. The distance in the finished roll between the perforations 27 may, of course, be varied as desired, and the axial length of a finished roll may well be varied; however, as an example, if it is desired to make toilet tissue rolls of 4-% inches in axial length with the distance between the transverse slits or perforations also 4- /2 inches, parent rolls approximately 20 feet in axial length would have about 50 of the perforated slits. Assuming that toilet tissue rolls of 500 two-ply sheets are desired from the apparatus, there would be two staggered rows of parent rolls, each roll having a combined length of about 2,250 inches or about 188 feet. Where it is desired to manufacture towels, which also may have one or more plies, larger spacings and axial lengths are, of course, contemplated.

Belts 30, 32, 34, etc. underlie the mandrel and the paper thereon both for supporting their combined weight and for moving the web 28a, etc. Power is preferably applied to all of the belts by drivingly rotating one of the rolls 66, 68, 70, 72 for the particular belt. Power may also be supplied to parent rolls 20a, 20b, 20c, etc. tending to unwind the webs from the rolls.

One type of paper illustrative of those products which may utilize the present invention is toilet tissue, an example of which is a creped tissue having a drier basis weight (single ply, in uncreped condition) of 7 to 8 pounds per ream of 2,880 square feet. The tissue is creped off of the steam heated drier drum of the papermaking machine so that it has a crepe ratio of 1.2 to 1.4, for example. This type of paper, in particular, also has a very different strength in the machine direction, that is, in the direction in which the paper travels through the Fourdrinier papermaking machine, over the steam heated drier drum of the machine and in which it is wound in rolls, such as, for example, rolls 20a, 20b, 200, etc., as compared to the strength of the paper in the transverse or cross machine direction. Paper of this type may, for example, be able to withstand 10.4 ounces per inch per ply before breakage in the machine direction or longitudinally of the web while it is only able to withstand 2.4 ounces per inch per ply in the cross machine direction before breakage. The ratio of the machine direction strength to the cross machine direction strength thus is 10.4/2.4 or about 4 to l.

As is apparent from the description of our winding apparatus, the perforations 27 of the finished web are provided by longitudinal slits as well as by the side edges of the individual webs. These slits 27 thus extend exactly in the machine direction and exactly transverse on the consumer roll as it is unwound; thus the paper bonds provided by the spaced notches 56a in the slitter wheels 56 are very easily broken so that, in usage, it is very easy to separate the individual sheets defined by the perforations 27 from the remainder of the roll. As will be understood, the force applied by the user tending to separate the individual sheets from the roll is applied substantially in the cross machine direction of the tissue paper used in the roll, this being the direction in which the paper is particularly weak; and, therefore, the bonds easily break. Consumer length toilet tissues as produced by conventional apparatus and methods have the tissue paper unwinding from the roll in the machine direction (as the paper is produced on the papermaking machines). Therefore, greater force must be utilized in detaching the individual sheets from conventionally made toilet tissue rolls due to this fact; and in addition, the paper is more likely to shred longitudinally due to the great strength in thebgnds between the individual sheets of ordinary t issue when the tissue is made conventionally. The fact that the transverse perforations 27 in our finished web extend in the machine direction, thus, is advantageous.

The fact that the tissue paper tears so much more easily in the cross machine direction than in the machine direction may also be utilized for providing consumer length rolls of toilet tissue or paper toweling in which there are no transverse perforations; instead the easy separability of the webs in the cross machine direction or in the longitudinal direction as the paper is disposed on the consumer length rolls according to our invention may be relied on so that individual pieces of paper may easily be torn from the remainder of the roll of paper as desired.

In this case the gang slitters 26 are dispensed with, and each of these slitters is replaced by an embossing device, for example, as illustrated and described in U. S. Pat. No. 3,477,658, particularly with reference to col. 6, line 32 to col. 7, line 17, which is incorporated herein by reference.

In the manufacture ofa single ply sheet where it is desired that the finished product be continuous, it may be desirable to bond the edges of sheets from adjacent parent rolls. There are many known bonding methods suitable for our purposes. For example, the sheets may be overlapped slightly and adhered by embossing, perforating, adhesive application, or the formation of chemical bonds. Other bonding steps will suggest themselves to those skilled in this art, and the foregoing are mentioned as illustrations only and are not to be construed as limited our invention.

Although our invention has been described in detail by reference to such sheets having a very substantial difference in strengths of 4 to 1 between the machine direction and the cross direction of the web, it is apparent that the recited advantages still result to some degree when the strength difference is of a lesser magnitude. Virtually all paper produced by conventional methods exhibit this strength differential to some degree. And, in fact, the very significant benefits in increased winder capacity, reduced machine wearQand slower operating speeds, will be derived from our invention regardless of the sheet properties so long as it possesses sufficient strength to be wound.

Having described our invention, it will be apparent that various modifications may be made without departure from its spirit and scope. Except as limited by the claims, such modifications are intended to form a part of our invention.

We claim:

1. A method of winding sheet material into rolls comprising the steps of,

providing one or more substantially continuous sources of said sheet material forming a combined sheet having a total width equal to the desired length of each of the wound rolls;

moving said combined sheet past a station for one or more mandrels which are initially positioned proximate the edge of said sheet;

slitting said combined sheet in a cross-deckle direction diagonally across said combined sheet; and

rotating each mandrel while moving it linearly on a diagonal path across said sheet as it is being slit so as to wind up said slit material; said mandrels being spaced and rotated in conjunction with the movement of said sheet so as to continuously provide wound rolls of said desired length.

2. The method of claim 1 wherein the substantially continuous sources comprise supply rolls which are unwound substantially edge to edge to form said combined sheet.

3. The method of claim 2 wherein said edges are overlapped.

4. The method of claim 2 wherein two or more sets of supply rolls are supplied in staggered relationship so that a substantially continuous sheet having a plurality of plies is formed when the sets of supply rolls are unwound.

5. The method of claim 1 wherein said combined sheet is perforated longitudinally before being slit in the cross-deckle direction.

6. The method of claim 1 wherein said material is tissue.

7. The method of claim 5 wherein said wound up slit material is further divided along its longitudinal length to form consumer size rolls.

8. The method of claim 4 wherein said multiple-ply sheet is embossed longitudinally before being slit in the cross-deckle direction.

9. Apparatus for producing rolls of sheet material, comprising,

one or more supply rolls rotatablly supported so that,

when unwound, they form a combined sheet having a total width equal to the desired length of said finished roll material;

sheet support means movably adapted to receive said combined sheet and to support it while unwinding;

one or more cross-deckle slitters positioned to cut said combined sheet in a direction diagonally across said combined sheet; and

one or more mandrels for winding up said cut combined sheet along a diagonal path as the combined sheet moves on said support means, said mandrels being spaced and adapted to rotate in conjunction with the movement of said sheet material so as to continuously produce wound rolls of said desired length.

10. Apparatus of claim 9 including two or more sets 12. Apparatus of claim 10 including sheet length emof supply rolls in staggered position to unwind a combossers for bonding said plurality of plies. posite sheet having a plurality of plies. 13. Apparatus of claim 9 including additional means 11. Apparatus of claim 9 including sheet length slitfor bonding sheets from adjacent supply rolls.

ters for perforating said sheet material as it unwinds. 5

PWBBG i GFFECE @ERTMQME 0F QoRR'E March'zs, 1974 Patent No 3 w 799 w 4 5 Dated Enventofls} it is certified that error appears in the above -identified patent and? hat said Letters Patent are hereby corrected as shown below:

Ira. capley Charles T; Banks, Jorg F. Voss fiobetract, line 2}"parent should real v-- such Signed arid sealed this 10th da of September 1974;

ZfcEOY 1 1. GIBSON; 3R. c. MARSHALL DAMN ibesclng Offlc er Commissioner of Patents 

1. A method of winding sheet material into rolls comprising the steps of, providing one or more substantially continuous sources of said sheet material forming a combined sheet having a total width equal to the desired length of each of the wound rolls; moving said combined sheet past a station for one or more mandrels which are initially positioned proximate the edge of said sheet; slitting said combined sheet in a cross-deckle direction diagonally across said combined sheet; and rotating each mandrel while moving it linearly on a diagonal pAth across said sheet as it is being slit so as to wind up said slit material; said mandrels being spaced and rotated in conjunction with the movement of said sheet so as to continuously provide wound rolls of said desired length.
 2. The method of claim 1 wherein the substantially continuous sources comprise supply rolls which are unwound substantially edge to edge to form said combined sheet.
 3. The method of claim 2 wherein said edges are overlapped.
 4. The method of claim 2 wherein two or more sets of supply rolls are supplied in staggered relationship so that a substantially continuous sheet having a plurality of plies is formed when the sets of supply rolls are unwound.
 5. The method of claim 1 wherein said combined sheet is perforated longitudinally before being slit in the cross-deckle direction.
 6. The method of claim 1 wherein said material is tissue.
 7. The method of claim 5 wherein said wound up slit material is further divided along its longitudinal length to form consumer size rolls.
 8. The method of claim 4 wherein said multiple-ply sheet is embossed longitudinally before being slit in the cross-deckle direction.
 9. Apparatus for producing rolls of sheet material, comprising, one or more supply rolls rotatably supported so that, when unwound, they form a combined sheet having a total width equal to the desired length of said finished roll material; sheet support means movably adapted to receive said combined sheet and to support it while unwinding; one or more cross-deckle slitters positioned to cut said combined sheet in a direction diagonally across said combined sheet; and one or more mandrels for winding up said cut combined sheet along a diagonal path as the combined sheet moves on said support means, said mandrels being spaced and adapted to rotate in conjunction with the movement of said sheet material so as to continuously produce wound rolls of said desired length.
 10. Apparatus of claim 9 including two or more sets of supply rolls in staggered position to unwind a composite sheet having a plurality of plies.
 11. Apparatus of claim 9 including sheet length slitters for perforating said sheet material as it unwinds.
 12. Apparatus of claim 10 including sheet length embossers for bonding said plurality of plies.
 13. Apparatus of claim 9 including additional means for bonding sheets from adjacent supply rolls. 